I need help!!

Hey guys. I need some help. So I'm currently on cd27. I have really irregular and long cyclea because I am breastfeeding. I got some very positive opks today and now all of the sudden I am cramping so badly and getting so nauseous. It literally feels like I'm on my period and have morning sickness at the same time. I have never cramped like this during ovulation before. Any idea what could be going on??